Working with a database accompanies any more or less complex project. The database acts as a repository of information, which contains all the necessary parameters for the correct operation of the system. And what are the most common practices in practice? When are they used? These and other questions will be answered in the framework of this article.
general information
So, for starters, you need to decide what the program in question is. A database is a name for the ordered storage of arbitrary information. It can be organized not only with the help of IT-technologies, but also in other ways and methods. But at the same time, the principle of systematization should be used as a basis.
It should be noted that there are many possibilities for organizing and storing data. Each of the methods puts forward certain requirements. There are databases that are aimed at autonomous operation within a single computer. Others involve interaction with a remote server. If we talk about architecture, the most common are hierarchical and network databases. In this article, they will be emphasized.
Hierarchical databases
The architecture of the system in this case provides that each object is represented as a specific entity. Due to this, it can have parent or child elements. A feature of this architecture is that there must be one object from which it all begins. The result is a structure that resembles a tree. Almost any old program will help you understand how such an organization works. A database of this type is also a computer file system.
You can often hear that the use of such a structure is not something effective. Nevertheless, it is still widely used. This is due to the fact that working with a database is beneficial when it is necessary to primarily read information. Indeed, in this case, the construction structure is extremely conducive to this. As an example, let's look at this situation: when we select a specific folder, then the interaction occurs quickly. But if we run an anti-virus computer scan, it will last a very long time.
Network Databases
This is a kind of modification of the previously considered example. The main difference here is the number of links. So, in hierarchical databases it is provided that one element can have only one parent. Thus, we can talk about a certain constraint in the development of the database. Network databases can have several parents. This is more relevant for creating a database based on XML.
Relational databases
The most common in practice are they, in terms of mass use, editing, and so on. The reason for their popularity is that relational databases are very easy to describe in mathematics. Due to the ease of implementation, they are widely used.
The theoretical basis for them was brought by the mathematician Edgar Frank Codd (now deceased). In the eighties, he was able to very detailed and qualitatively describe the structure of such databases, using the mathematical language. And as practice shows, such a justification is a good basis for software implementation. Relational databases have become so popular that when they talk about databases, they understand them by default. Let's pay attention to the specifics of their implementation.
Features of relational databases
Their main distinguishing feature is that the data is stored as sets of two-dimensional tables. As a simple example, the Access database included in the Microsoft office suite can be given. Columns and rows are used as alpha and omega. The peculiarity of the former is that through them the name of the fields, the type of data that they use are indicated. In addition, the number of columns is fixed and can only be changed with DB administrator privileges. Lines are objects of information. Their number changes relatively easily through the provision of special instructions.
It must be understood that the database is an abstract concept. Therefore, the most common in practice are databases in which tables are related. A very good graphical representation in this matter can be given by Access mentioned earlier. The most important aspect when working is the design of the structure. This process is to create the elements mentioned above. It should be noted that this is a difficult stage, which many beginners take lightly. And in vain. After all, while there is little data, they will be processed quickly by a computer. But as the amount of information increases, a slowdown will be noticeable. Its value will be directly proportional to the size of the stored data and the optimality of the structure.
Database Design
So, we have considered the most popular options for building a database. Now let’s talk about which approaches are most common in practice when they are created and why. As an example, consider MySQL. So, there are such requirements for the final result:
- The database should be a simple object in terms of processing.
- The database should be compact in size.
With experience, it is easy to notice that these concepts are contradictory. First you need to understand exactly what will be transferred to the database and removed from it. In serious projects, you can find dozens and hundreds of tables with an incredible number of objects. The following issues should be addressed:
- Determine what data will be stored.
- Find out where the information will be posted.
- Decide which data type to select for an individual column.
To reduce the load, you can use the breakdown into separate tables. But you need to make sure that there are certain unifying components.
Conclusion
Databases are important components of any more or less complex project. Initially, in practical implementation, a person may not be able to organize the optimal connection. But over time, when studying this area and increasing experience, it will already be possible to create more advanced objects.
Also, one should not disregard the fact that more advanced program structures are gradually being offered. In addition, database management systems can provide feasible assistance in optimization . They provide the developer with wide functionality, with the help of which almost any task can be performed. The variety of DBMSs is quite large, so you can choose exactly what you like.